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IEEE Bash Scripting

### Compiled vs Interpreted languagess
            | Compiler | Interpreter |
            | -------- | ----------- |
            | "Compiles" down a program into binary (machine code) |  Does not save machine langauge |
            | Must first compile a program into machine code before running | Interprets each line and executes each as it reads them |
            | Tries to make use of the cpu it compiles a program for | Usually less finetuned for a CPU |
            | Usually favored in production | Usually favored in development and programming environments |

Compiled vs Interpreted Example

program.c program

#include <stdio.h>
  int main() {
  int a = 36;
  int b = 6;
  printf("The answer to life, the universe,\
  and everything: %d\n", a+b);
  return 0;
  }

$ gcc program.c -o program

program.py

a = 36;
  b = 6;
  print("The answer to life, the universe,\
   and everything: {}".format(a+b))

$ python everything.py
  The answer to life, the universe, and everything: 42

Compiled vs Interpreted Example

program.c program

#include <stdio.h>
  int main() {
  int a = 36;
  int b = 6;
  printf("The answer to life, the universe,\
  and everything: %d\n", a+b);
  return 0;
  }

$ gcc program.c -o program
$ ./program
We know the answer is 42, but what is the question?

program.py

a = 36;
  b = 6;
  print("The answer to life, the universe,\
   and everything: {}".format(a+b))

$ python everything.py
  The answer to life, the universe, and everything: 42

TODO: Show how there exists a python shell

TODO: Entering commands into terminal example example

How programs can be called: firefox, steam, discord, grep

TODO: Go list what are some commands line by line

cd ls echo/printf

TODO: Go list what are some commands line by line CONTD.

cat, other commands we might use in the scripts

TODO: Explain how command shells there are: zsh on mac, Powershell and Command Line Prompt on Windows, and Bash, then more alternatives

POSIX IEEE 1003.1 (2017)

TODO: Funny Yash shell

Control Logic

If Statement:

if COMMAND; then
  # Insert more commands here
fi

Control Logic

If Statement:

if COMMAND; then
  # Insert more commands here
fi

if COMMAND; then
  # Insert more commands here
else
  # Do otherwise
fi

Control Logic

If Statement:

if COMMAND; then
  # Insert more commands here
fi

if COMMAND; then
  # Insert more commands here
else
  # Do otherwise
fi

if [[ 2 -eq 2 ]]; then
  # Insert more commands here
else
  # Do otherwise
fi

TODO on these things

- Piping - If Statement: - && and || - For loops: - How the scripts actually work - functions, associative arrays, string substition, etc. - Look at a good cheatsheet

TODO: Give good resources on bash cheatsheets: https://devhints.io/bash

TODO: mild script example 1

TODO: mild script example 2

TODO: mild script example 3

TODO: rclone

TODO: httpd servers

TODO: wget

TODO: combining wget and http to mirror sites

Get every Canvas file from your course!

Here's a script to download all files for a given Canvas course. You will need to get an API Token from Canvas for UCSD and the course ID. To get the course ID, take the ID from the course's URL. Go to your browser, open your course page, you will get a URL like this: https://canvas.ucsd.edu/courses/123456 The ID is the number at the end. Place it at the end of the variable COURSE_ID below with quotes. For the API token, click on your profile picture, then click "Settings". After that, create a "New Access Token" under the "Approved Integrations" section. Add a name and expiration date. You will get a token on the dialog after that looks something like this: "12345~..." Just put it down in the variable API_TOKEN below. This uses "jq" to filter the JSON received into a readable format for our script. '.[]' takes every element from the array and lists it line-by-line, while the second part creates a string containing the fields from the request, comma-delimited. Try running the command above on its own and experiment with different "jq" queries. There are cheat sheets online you can find, it's cool! For each line from the above query, we'll get the filename and the URL. Then, for all of them, we will download the file in the directory "files/" and just name it as-is on the page. The line variable looks something like this: "NAME OF FILE,URL TO DOWNLOAD FILE" Awk is a scripting language for text manipulation. You can use to quickly parse comma-delimited values, which is what I do below. Download the file and move it to the files directory. "-s" silences the progress bar that shows up with cURL, you can remove the "-s" to see it.

#!/usr/bin/env bash

COURSE_ID="123456"
API_TOKEN="12345~..."

mkdir -p files/

FILES=$(
	curl
	-X GET
	-H "Authorization: Bearer $API_TOKEN" \
		https://canvas.ucsd.edu/api/v1/courses/$COURSE_ID/files |
		jq -r '.[] | "\(.filename),\(.url)"'
)

echo "$FILES" | while IFS= read -r line; do
	FILENAME=$(echo $line | awk -F',' '{print $1}')
	URL=$(echo $line | awk -F',' '{print $2}')
	echo "Downloading $FILENAME..."
	curl -s "$URL" -o "$FILENAME"
	mv "$FILENAME" "files/$FILENAME"
done

echo "Done! All your files are in the 'files/' directory."

TODO: Plug in how bash is essential to supercomputing

TODO: Plug in SCC Apps and also our website

TODO: Thank you Slide

WARNING: Slides after this are just for debugging and messing with layouts,css,js,etc.

Trying to braek the bounds of the perhaps margin on this thing. They contain the maximum size of content for slides.

Example Script

#!/bin/bash
# Descr: Bash Script for Bash Workshop
printf "Hi, how are you doing?\n"

firefox

wget -k -m -r https://ieeeucsd.org/

#!/bin/bash
# Descr: Bash Script for Bash Workshop
printf "Hi, how are you doing?\n"

firefox

wget -k -m -r https://ieeeucsd.org/

HStack Example

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